Processing facilities are often managed using process control systems. Example processing facilities include manufacturing plants, chemical plants, crude oil refineries, and ore processing plants. Among other operations, process control systems typically manage the use of motors, valves, and other industrial equipment in the processing facilities.
In some process control systems, components are divided into a hierarchy of levels, referred to as “network levels.” Components in different network levels are typically responsible for performing different types of functions in the process control systems. For example, a conventional process control system could include one or more Level 1 network levels and one or more Level 2 network levels. As particular examples, a Level 1 network level may include controllers and other components used to control the industrial equipment. A Level 2 network level may include servers, personal computers, and other components used to interact with and control the components in the Level 1 network level.
It is often important to protect more critical components of the process control systems (such as components in Level 1 network levels) from virus attacks or other disruptions. One prior approach involves providing separate switches for the more critical components and for the less critical components of the process control system. However, this approach often increases the complexity and cost of the process control system because multiple sets of switches are required.